The present invention relates to apparatus for driving tunnels, galleries, adits, roadways or other underground excavations, all collectively referred to, for convenience, as "tunnels."
It is known to utilize tunnel driving apparatus which has a shield supporting the forward region of the tunnel wall and protecting a cutting machine which cuts away the full cross-section of the tunnel from a working face. Examples of such known types of apparatus are described in German Pat. Nos. 1534602 and 1279053. Where tunnels of relatively large cross-section, say 8-12 meters in diameter, are to be driven, the cutting machine needs to be of large and robust construction in order to cut over the full working face. This gives rise to various problems, primarily with the guidance and support of the machine. To overcome this problem, a cutting machine just cutting over a central region of the working face can be used. Such apparatus is known from German Pat. No. 2437669. This known apparatus utilizes a cutting machine with a cutting arm or jib pivoted to a support which, in turn, is able to move about an axis coincident with the central tunnel axis. The cutting arm support is guided for advancement or retraction in the direction of the tunnel. Since the cutting machine is only designed to cut away part of the working face, it can be relatively small and of light construction so that the guidance and mounting thereof does not present difficulties. Where a tunnel of relatively large size is to be driven, it is necessary, however, to utilize several cutting machines each acting on part of the working face. Such an arrangement is known from German Pat. No. 2431652. With regard to the foregoing, there is a need for a versatile tunnel driving apparatus which is able to drive tunnels of large or small size with various cross-sectional shapes without excessive cost or complex construction. A general object of this invention is to provide such an improved form of tunnel driving apparatus.